By Tyler Tafelsky
One of the most common questions asked among beginner triathletes is, “what are the differences between a road bike and a triathlon bike?
For those just entering the multisport world, such as triathlon, duathlon, or even quadrathlon – the bike leg makes up the largest segment of the race. In fact, the bike leg in most triathlon events represents about 50-60% of the total time invested in a given race.
There are many reasons why triathlon bikes are preferred over road bikes for such events. While road bikes are more appropriate for pack riding and drafting with a group, the geometry of triathlon bikes is better suited for time trial efforts. This is why triathlon bikes and time trial bikes (or “TT bikes”) are practically synonymous with one another.
Triathlon Bikes: All About the Time Trial
When compared to road bikes, the geometry of triathlon bikes has distinct frame design and athlete positioning. Of these frame differences, triathlon bikes have a steeper seat tube angle, which puts athletes in a more aggressive and aerodynamic position. The seat tube angle (or “STA”) on triathlon bikes often exceeds 78 degrees, while on road bikes, it’s closer 72 degrees.
Compounded by the effects of a steeper and more aggressive seat tube angle, it’s also common for the saddle height on triathlon bikes to be positioned substantially higher than that of road bikes. This higher-up position further promotes a more horizontal, aerodynamic position while also widening the athlete’s hip angle.
In the case of multisport racing like triathlon or duathlon, this widened hip angle produces biomechanical efficiencies that help improve run performance off the bike. Studies have shown that a steeper STA can help conserve and optimize primary muscle groups that facilitate running performance.
The advantage multisport athletes have in using a time trial/triathlon bike versus a road bike is two-fold. Not only does a steeper STA help improve running performance off the bike, but the position of cyclists on a time trial bike is naturally more aerodynamic.
This can be particularly beneficial for athletes who are training and racing long-course triathlon, such as Ironman distances. Average bike splits for Ironman age groupers can range between 5-7 hours (and 4-5 hours for professionals), which is a substantial amount of time on the bike. Any advantage that can be earned with less drag and greater cycling economy will pay dividends in Ironman events, which conclude with a full marathon run leg.
Not All Triathlon Bikes Are Created Equal
While triathlon bikes and time trial bikes are mostly one in the same breed, not all triathlon bike builds are legal to ride in every time trial event.
Most time trial events, which are typically part of tour riding and not multisport events, are governed by International Cycling Union (UCI) regulations.
UCI-legal time trial bikes must have the tip of the saddle nose within 1.97 inches or 5 centimeters from the center of the bottom bracket. Some extremely aggressive TT bikes might fall outside of this qualification, making them illegal to use in UCI sanction events.
For most triathletes and multisport athletes, this is seldomly an issue. Today’s technology of triathlon bikes continues to push the envelope in terms of geometry and composition. And bikes are becoming increasingly fast and lightweight every year.
As in the case of modern triathlon bikes, the differences in frame design are often very obvious to the eye compared to that of road bikes. Newer model triathlon bikes have dramatically more narrow, thin, and tapered frames and forks, which also provides a more aerodynamic position.
Should You Invest in a Triathlon Bike?
Let’s be real. For many athletes investing in their first bike, the cost of buying a new triathlon bike is not far from a full month’s income. Entry-level and beginner triathlon bikes can cost between $2,500-$4,000 new, and higher performance options can easily exceed $5,000 or more.
Not only are road bikes more affordable, but there are typically a lot more used options available on the market. For most beginners, a $1,000 or less road bike is a perfectly fine place to start. But for serious triathletes, investing in a triathlon bike is certainly worthwhile long-term, especially for long-course events.
Author Bio
Tyler Tafelsky is the lead editor of Better Triathlete, an online triathlon community that provides information and resources surrounding training, coaching, equipment, and gear.
Images:
Unsplash/ Tony Pham: https://unsplash.com/photos/pzKVmt9ziT8
Pixabay/ pontzi: https://pixabay.com/photos/cycling-cliclista-cyclists-2756598/